Most batteries are intrinsically low capacity systems despite their use of low molecular weight (e.g. lithium or zinc anode) materials. The utilization of an air cathode, where the cathode active material is stored outside the battery is one way in which to enhance the overall battery capacity. Air cathode batteries could drastically impact applications that demand a rugged, safety-focused, low weight, small volume, high energy-density power source. However, several technical challenges hinder such batteries. The first challenge lies in the cathode current collector, which brings oxygen into the cell using ambient air and serves as the substrate for the metal-oxygen reaction. Typically, the cathode consists of a porous carbon layer which may contain catalyst particles. Current research has not yet determined the optimal pore size for the cathode current collector or the specific mechanism responsible for enhancing the lithium-oxygen reaction by catalysts. The second challenge lies in the choice of electrolyte. Most lithium-air batteries utilize an organic electrolyte because of its fast lithium ion conduction; however, this approach results in “clogging” of the cathode current collector pores and reduced battery energy density due to insolvency of the lithium peroxide. Additionally, organics react with oxygen and the metal anode over time, causing unwanted side reactions.